Key Note: The iconic burger raises your blood sugar, dehydrates you, and makes you feel hungry again just 40 minutes after eating it.
The First 10 minutes: The Big Mac (and its 540 calories) raises your blood sugar to abnormal levels. Junk food like the Big Mac triggers your brain’s reward system by releasing “feel-good” chemicals, such as the neurotransmitter dopamine. The process works in a similar way to the reaction you’d get after taking a drug like cocaine and raises the likelihood of compulsive eating.
After 20 minutes: The Big Mac’s bun has high levels of high-fructose corn syrup and sodium — both of which are addictive and make your body crave more.
After 30 minutes: The burger’s 970 milligrams of sodium can cause dehydration. The symptoms of dehydration are similar to those of hunger, tricking you into thinking you want more food. Your kidneys have trouble eliminating the salt, and your heart has to work faster to pump blood through your veins. This can cause high blood pressure and can ultimately lead to heart disease and stroke.
After 40 minutes: You start to feel hungry again. When you eat a high calorie meal, your body’s insulin response can bring down your glucose levels, causing you to want to eat more. The bun’s high-fructose corn syrup is quickly absorbed by your GI tract, creating insulin spikes and even bigger hunger pangs.
After 60 minutes: Your body typically takes 24 to 72 hours to digest food, but burgers can take more time because they are greasier. The Big Mac can take more than three days to fully digest.